﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Json;
using System.IO;
using System.Text.RegularExpressions;

namespace PracticeCentre.Common
{
    public class JsonTool
    {
        /// <summary>  
        /// 对象转Json  
        /// </summary>  
        /// <typeparam name="T">对象类型</typeparam>  
        /// <param name="t">序列化对象</param>  
        /// <returns></returns>  
        public static string JsonSerializer<T>(T t)
        {
            DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(T));
            MemoryStream ms = new MemoryStream();
            ser.WriteObject(ms, t);
            string jsonString = Encoding.UTF8.GetString(ms.ToArray());
            ms.Close();
            string p = @"(?<=\()((?<gp>\()|(?<-gp>\))|[^()]+)*(?(gp)(?!))";
            MatchEvaluator matchEvaluator = new MatchEvaluator(ConvertJsonDateToDateString);
            Regex reg = new Regex(p);
            jsonString = reg.Replace(jsonString, matchEvaluator);
            jsonString = jsonString.Replace(@"\/Date(", "").Replace(@")\/", "");
            return jsonString;
        }

        /// <summary>  
        /// Json转对象 
        /// </summary>  
        /// <typeparam name="T">对象类型</typeparam>  
        /// <param name="jsonString">反序列化json字符串</param>  
        /// <returns></returns>  
        public static T JsonDeserialize<T>(string jsonString)
        {

            string p = @"\d{4}-\d{2}-\d{2}\s\d{2}:\d{2}:\d{2}";
            MatchEvaluator matchEvaluator = new MatchEvaluator(ConvertDateStringToJsonDate);
            Regex reg = new Regex(p);
            jsonString = reg.Replace(jsonString, matchEvaluator);
            DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(T));
            MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(jsonString));
            T obj = (T)ser.ReadObject(ms);
            return obj;

        }

        private static string ConvertJsonDateToDateString(Match m)
        {
            string result = string.Empty;
            DateTime dt = new DateTime(1970, 1, 1);
            string str = m.Groups[1].Value.Substring(0, m.Groups[1].Value.IndexOf("+"));
            dt = dt.AddMilliseconds(long.Parse(str));
            dt = dt.ToLocalTime();
            result = dt.ToString("yyyy-MM-dd HH:mm:ss");
            return result;
        }

        private static string ConvertDateStringToJsonDate(Match m)
        {
            string result = string.Empty;
            DateTime dt = DateTime.Parse(m.Groups[0].Value);
            dt = dt.ToUniversalTime();
            TimeSpan ts = dt - DateTime.Parse("1970-01-01");
            result = string.Format("\\/Date({0}+0800)\\/", ts.TotalMilliseconds);
            return result;
        }
    }
}
